/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.skatiger.jrove.compiler;

import java.io.IOException;
import java.io.Writer;

import javax.el.ELException;

import org.skatiger.jrove.JroveContext;
import org.skatiger.jrove.JroveException;
import org.skatiger.jrove.component.UIComponent;
import org.skatiger.jrove.el.ELText;
import org.skatiger.jrove.util.ComponentSupport;
import org.skatiger.jrove.util.FastWriter;

/**
 * @author Adam Winer
 * @version $Id: UIInstructionHandler.java,v 1.6 2008-07-13 19:01:33 rlubke Exp
 *          $
 */
final class UIInstructionHandler extends AbstractUIHandler {

    private final String alias;

    private final String id;

    private final ELText txt;

    private final Instruction[] instructions;

    private final int length;

    private final boolean literal;

    public UIInstructionHandler(String alias, String id, Instruction[] instructions, ELText txt) {
        this.alias = alias;
        this.id = id;
        this.instructions = instructions;
        this.txt = txt;
        this.length = txt.toString().length();

        boolean literal = true;
        int size = instructions.length;

        for (int i = 0; i < size; i++) {
            Instruction ins = this.instructions[i];
            if (!ins.isLiteral()) {
                literal = false;
                break;
            }
        }

        this.literal = literal;
    }

    public void apply(JroveContext ctx, UIComponent parent) throws IOException, JroveException, ELException {
        if (parent != null) {
            // our id
            String id = ctx.generateUniqueId(this.id);

            // grab our component
            UIComponent c = ComponentSupport.findChildByTagId(parent, id);
            boolean componentFound = false;
            if (c != null) {
                componentFound = true;
                // mark all children for cleaning 
                ComponentSupport.markForDeletion(c);
            } else {
                Instruction[] applied;
                if (this.literal) {
                    applied = this.instructions;
                } else {
                    int size = this.instructions.length;
                    applied = new Instruction[size];
                    // Create a new list with all of the necessary applied
                    // instructions
                    Instruction ins;
                    for (int i = 0; i < size; i++) {
                        ins = this.instructions[i];
                        applied[i] = ins.apply(ctx.getExpressionFactory(), ctx);
                    }
                }

                c = new UIInstructions(txt, applied);
                c.setId(id);
                c.getAttributes().put(ComponentSupport.MARK_CREATED, id);
            }
            // finish cleaning up orphaned children
            if (componentFound) {
                ComponentSupport.finalizeForDeletion(c);
                parent.getChildren().remove(c);
            }
            this.addComponent(ctx, parent, c);
        }
    }

    public String getText() {
        return this.txt.toString();
    }

    public String getText(JroveContext ctx) {
        Writer writer = new FastWriter(this.length);
        try {
            this.txt.apply(ctx.getExpressionFactory(), ctx).write(writer, ctx);
        } catch (IOException e) {
            throw new ELException(this.alias + ": " + e.getMessage(), e.getCause());
        }
        return writer.toString();
    }

    @Override
    public String toString() {
        return this.txt.toString();
    }

}
